Can you fail a hair drug test from secondhand smoke
Can You Fail a Hair Drug Test from Secondhand Smoke? Understanding Passive Exposure Risks
Can you fail a hair drug test from secondhand smoke? Hair drug tests are designed to detect active drug use, not casual or environmental exposure such as secondhand smoke. Passive exposure alone rarely causes a positive hair test result. For questions or testing, call (877) 731-6362.
What is a hair drug test and how does it work?
A hair drug test analyzes a small sample of hair to detect drug metabolites deposited in the hair shaft from bloodstream exposure. It typically covers drug use over the past 90 days, depending on hair length. Hair testing is often used by employers, courts, and probation agencies due to its longer detection window compared to urine or saliva tests.
The test is performed by one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox. AMH Nationwide facilitates lab orders and directs individuals to nearby collection sites for sample collection.
Can secondhand smoke cause a positive hair drug test?
Secondhand smoke exposure is generally insufficient to cause a positive hair drug test. Hair testing detects drug metabolites incorporated internally from the bloodstream, not just external contamination. Passive environmental exposure typically does not result in enough metabolite concentration within hair to trigger a positive result.
How do labs prevent false positives from environmental contamination?
Labs follow strict protocols to minimize false positives from external contamination. Hair samples undergo washing steps to remove surface contaminants such as smoke residue or dust. Only metabolites incorporated inside the hair shaft from the bloodstream are measured.
Additionally, all non-negative hair drug test results are reviewed by a certified Medical Review Officer (MRO). The MRO evaluates potential alternative explanations, including environmental exposure, before confirming a positive result.
What is the detection window for hair drug tests compared to other tests?
Hair drug tests typically detect drug use within the past 90 days, depending on hair length. This is longer than urine tests (1-4 days for most drugs) and saliva tests (up to 48 hours). Hair testing is less affected by short-term exposure and is designed to confirm repeated or chronic drug use.
| Test Type | Typical Detection Window |
|---|---|
| Hair Drug Test | Up to 90 days |
| Urine Drug Test | 1-4 days |
| Saliva Drug Test | Up to 48 hours |
Need Accurate Hair Drug Testing?
Contact AMH Nationwide to arrange hair drug testing with certified labs and expert Medical Review Officer analysis. Call (877) 731-6362.
Is hair testing allowed for DOT-regulated safety-sensitive positions?
No. The Department of Transportation (DOT) requires federally certified urine drug testing under 49 CFR Part 40 for safety-sensitive positions. Hair testing is not accepted for DOT-regulated roles but may be used for non-DOT employment or other purposes.
How do I get a hair drug test through AMH Nationwide?
AMH Nationwide provides lab orders for hair drug testing and directs individuals to one of over 20,000 collection sites nationwide. There is no online ordering available. To schedule or inquire about hair drug testing, call (877) 731-6362. Pricing varies by test panel and detection window.
Common Questions
It is highly unlikely. Hair tests detect metabolites from drug use incorporated internally. Passive marijuana smoke exposure rarely delivers enough drug to bloodstream to cause a positive hair drug test.
Yes. Laboratories wash hair samples to remove external contaminants like smoke or dirt. This reduces the chance of false positives from environmental exposure.
Hair drug tests typically detect drug use up to 90 days prior, depending on hair length. This makes it suitable for detecting repeated or chronic use.
Hair testing is more reliable for detecting repeated drug use. One-time or very infrequent use may be below detection thresholds, especially if hair length is short.
No. Hair testing is accepted for many employers and courts but is not accepted for DOT-regulated safety-sensitive roles, which require federally certified urine testing.
Call AMH Nationwide at (877) 731-6362 to receive a lab order and find a nearby collection site. AMH does not offer online ordering.
Ready to get started?
AMH Nationwide provides the lab order and arranges collection nationwide. Every non-negative result reviewed by a certified Medical Review Officer. Call (877) 731-6362 or contact us.